Role of TGFbeta in Microtubule Dynamics

TGFbeta 在微管动力学中的作用

• 批准号: 7915833
• 负责人: Kathleen M Mulder
• 金额: $ 34.93万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7915833
• 关键词: Affect; Antineoplastic Agents; Arts; Back; Binding; Biological; Cancer Patient; Cell Cycle Inhibition; Cell Cycle Progression; Cell Nucleus; Cells; Characteristics; Complex; Cyclic AMP-Dependent Protein Kinases; DNA Synthesis Inhibition; DNA biosynthesis; Data; Defect; Development; Disease; Dyes; Dynein ATPase; Early Endosome; Endocytosis; Endosomes; Event; Family; Fibronectins; Figs - dietary; Future; Gene Targeting; Goat; Growth Factor; Human; Image; Immunoglobulin G; Impairment; In Vitro; Incubated; Intracellular Transport; Investigation; Left; Ligand Binding; Light; Link; MDCK cell; Malignant Neoplasms; Malignant neoplasm of ovary; Mediating; Microscope; Microscopy; Microtubules; Modeling; Motor; Mus; Mutate; Mutation; Nature; Normal tissue morphology; Nuclear; Nuclear Translocation; Organelles; Oryctolagus cuniculus; Pathway interactions; Phosphorylation; Phosphorylation Site; Phosphotransferases; Plasmids; Play; Preparation; Protein Isoforms; Proteins; Recruitment Activity; Regulation; Reporting; Resistance; Role; Serum; Signal Transduction; Signaling Molecule; Small Interfering RNA; Specific qualifier value; Specificity; Students; System; Testing; Thymidine; Time; Tissues; Transcriptional Regulation; Transfection; Transforming Growth Factor beta; Transmembrane Transport; Transport Vesicles; Vesicle; Western Blotting; base; cancer cell; cell growth; drug development; dynein light chain; functional outcomes; in vivo; innovation; knock-down; malignant phenotype; member; mutant; neoplastic cell; novel; oncology; receptor; research study; response; trafficking; tumor; tumor progression

DESCRIPTION (provided by applicant): A higher order of regulation can be achieved by compartmentalization and functional specialization of the endocytic pathway during signal transduction in response to growth factors (GFs). In contrast, impairment of intracellular (IC) trafficking of GF signaling complexes can result in mis-localization or accumulation of signaling molecules in the wrong compartment, or at the wrong time, giving rise to various disease states, including cancer. In addition, the specificity of motor protein light chains (LCs) in recruiting their membranous cargo for IC transport during regulation of GF signaling is becoming increasingly clear. Additional investigation of the regulation, key components, timing, and functional outcome of signaling from endosomal subcompartments is required to enable oncology drug development, based upon these newer signaling regimes. Our data from the last project period indicated that km23 dynein LCs are activated by TGF? receptors (T?Rs) and are required for Smad trafficking, prior to nuclear translocation. Thus, km23 appears to function as a "motor receptor" to recruit TGF? signaling complexes to the dynein motor for IC transport of cargo (ie, T?Rs, Smads) along microtubules (MTs) toward the nucleus. In addition, we have identified another related member of the km23/LC7/robl/DYNLRB family, termed km23-2. While this isoform appears to have some characteristics similar to km23-1, km23-2 appears to more specifically regulate Smad3, in contrast to Smad2 regulation by km23-1. The mechanisms underlying the differential regulation and trafficking of Smads2/3 in relation to the km23-1/2 motor LCs will be explored in the new application, including how km23 impacts downstream TGF? responses. During the last project period, we have also shown that protein kinase A (PKA) directly phosphorylates km23 and is required for km23 binding to the dynein intermediate chain (DIC). The mechanisms underlying this PKA phosphorylation of km23 in TGF? signaling and Smad2/3 trafficking will also be examined. Additional studies relate to the investigation of how these trafficking events are altered in human ovarian cancer cells (HOCCs) known to express altered forms of km23-1. As part of the last project period, we identified km23-1 alterations in 42% of ovarian cancer patient tissues, with no km23 alterations detectable in normal tissues. Such a high alteration rate in ovarian cancer suggests that km23 may play an important role in either TGF2 resistance or tumor progression of this disease. In the new application, we will examine the effects of knocking down km23, or mutating it at key phosphorylation sites, on Smad trafficking, Smad-specific TGF? responses, and the malignant phenotype of the human cancer cells in vitro, as well as on tumor progression in vivo.

描述（由申请人提供）：在响应生长因子（GFs）的信号转导过程中，内吞途径的区隔化和功能特化可以实现更高层次的调节。相反，细胞内GF信号复合物运输的损伤可导致信号分子错误定位或在错误的间隔或错误的时间积聚，从而引起包括癌症在内的各种疾病状态。此外，运动蛋白轻链（LCs）在调节GF信号传导过程中招募其膜货物进行IC运输的特异性正变得越来越清楚。基于这些新的信号机制，需要对内体亚室信号的调控、关键成分、时间和功能结果进行进一步的研究，以促进肿瘤药物的开发。